Originally Posted by arpinehb
I've had my blue tang for more than a year in this 30 gal tank and it seems that he is happy!
Paracanthurus hepatus reaches a foot long. Surely you can see a 30 gallon is insufficient for a fish this size? You are to be commended that it has survived this long in your little tank, despite the overfeeding that has led to your nematode infestation, but really, keeping one in a 30 is a disservice to the fish in the extreme. Tangs can live many, many years in captivity; seven or eight or more years isn't uncommon. Your tang will grow, and continue to do so in your cramped conditions to its detriment.
P. hepatus like most tangs in the hobby are pelagic species, that is they roam the reef en masse looking for algae to eat all day. Thus, they need maximum swimming room in aquariums to have any semblance of natural behavior.
I wouldn't keep a blue tang in anything under 200 gallons. You could get away with a yellow tang in a 90, but something as big as a blue tag needs considerable more space.
I know you want to keep your blue tang happy and healthy for years to come, so you owe it to him to give him the space he requires for full growth and health. A foot-long blue tang is a beautiful sight, one few viewers can forget.